Abstract: This invention provides a system which includes winding apparatus for haug in and paying out a substantially inextensible steel rope tethering a floating vessel to a moorage or towing vessel, and a control system responsive to signals indicative of the tension in the steel rope and of the length of rope paid out for controlling the winding apparatus. There is also provided an energy reservoir for receiving and storing energy from the winding apparatus when the rope is paid out. The control system operates such that the tension in the steel rope does not exceed a predetermined value.

Abstract: A crane with a crane rope; means for attaching a load to the crane rope; a crane winch having a drum on which the crane rope can be wound; a crane motor which can drive the crane winch for hauling in or letting out the crane rope; a measuring winch having a drum with a measuring line windable thereon of length sufficient to reach at least as far as the crane rope can reach; a measuring winch motor which can turn the measuring winch drum to wind in or out the measuring line; means for attaching the outer extremity of the measuring line, away from the drum, to the load to be lifted by the crane; first transducer means operated by the measuring winch to provide a displacement signal proportional to any change, in relation to a predetermined value, and having regard to sign, of the length of measuring line extending from the measuring winch drum to the load; and crane motor control means operable by the displacement signal to control the crane motor to haul in or let out the crane rope substantially in synchronis

Abstract: An automatic machine for operating upon a work piece at a predetermined ption with respect to a pre-selected physical feature, for example an edge, of the work piece. The machine scans the work piece and transmits signals corresponding to the co-ordinates of the physical feature to a computer. The computer thereafter controls in accordance with the signals received from the scanning head the position of the operating head, so that the operating head can operate upon the work piece at the pre-determined position with respect to the pre-selected physical feature.